Safety cap for pressurized gas tanks



April 8, 1953 c. H. FLUBACKER 2,636,634

SAFETY CAP FOR PRESSURIZED GAS TANKS Filed Sept. 8, 1949 J9 4 Jgi MTV 04 =-\l M I INVENTOR. (/zar/as flflaback r' BY WM Q%o'-/% Cliiys PatentedApr. 28, 1953 SAFETY CAP FOR PRESSURIZED GAS TANKS Charles H. Flubacker,Chicago, Ill., assignor to Cook Electric Company, Chicago, 111., acorporation of Illinois Application September 8, 1949, Serial No.114,665 I 7 Claims.

This invention relates to improvements in a safety cap for pressurizedgas tank whereby the pressure of the gas, air or the like in the tank,from whatever cause, is relieved befor the cap is removed.

Such tanks are apt to be deceptive as to the presence of sufiicientpressure therein to cause trouble if the cap is sought to be removed.Such pressure may result from various causes, as from the standing idleof the tank for a period with a small quantity of volatile liquidtherein, or from the failure of the pressure therein to discharge theliquid through the usual channel, such as a spray hose, for example,thus giving rise to the thought that the pressure in the tank isexhausted but in which there is still sufficient pres sure to causetrouble if the cap is attempted to be removed. Or, an operator may becareless or forgetful of the condition of the pressure in the tank. Inany such case the cap is apt to be blown skyward and the liquid splashedand thrown out, to the possible injury of the operator and damage to thetank, cap or surroundings.

It is an object of this invention to provide a cap construction for suchpressurized tanks having provision for bleeding the pressure in the tankbefore removal of the cap and so arranged as necessarily to so bleed thesame before the cap may be removed.

A further object of the invention is the provision of a cap constructionfor pressure tanks in which the cap has a peripheral holding and sealingengagement with the seat therefor attached to the tank opening, andcarries a normally closed bleeder valve which is opened by themanipulation of the cap handle or member in the attempted removal of thecap and which allows the pressure to escape before the cap is removed.

Further objects and advantages will appear from the description andclaims to follow, in connection with the accompanying drawing whichillustrates, by way of example but not of limitation, an embodiment ofthe invention, and in which- Fig. 1 is a plan view of the capconstruction with the cap in place on a tank;

Fig. 2 is a sectional elevation of the apparatus of Fig. 1, the plane ofsection being indicated by 2 the line 2-2 of Fig. 1, the hinged flap orhandle member of the cap and the bleeder valve being shown in theirnormal closed positions;

Fig. 3 is a similar section through the cap and valve but showing thehandle and valve in their raised and open positions; and

Fig. 4 is a detail sketch of the bayonet slot peripheral connectionbetween the cap and its seat.

In the drawing, the pressure tank [0, which may be of sheet metalpressed into usual form and of any desired size, as indicated in Fig. 2,is provided with an opening in the head or end II in which theperipheral ring seat I2 with its inner flange l3, U-shaped in crosssection, is fitted and secured to thetank head by welding, soldering, orthe like, to provide a strong, rigid, and sealed connection between tankand seat.

To provide a readily attachable and removable closure for this openingin the tank and in sealed relation thereto when applied, :a disc orplate-like cap I4 is provided with a peripheral inner flange 15 which isadapted to enter deeply into the U-ring I3 of the ring seat l2, as indicated in Fig. 2, when the cap is applied to the tank or drum [0. Theinner face of this flange I5 is provided with an annular groove l6 inwhich is located preferably a silicone O-ring type of gasket against thepassage of air or gas between the cap and seat notwithstanding anyclearance that may be present between the cap and seat ring flangesurfaces in the joint and the travel of the gas pressure from the insideof the tank to the O-ring. In fact, the greater the pressure the tighterthe seal. The silicon O-ring also facilitates the application andremoval of the cap, due to its ability to slide and roll on the surfaceswithout damage or loss of efiiciency.

The cap I4 is secured and retained in the seat ring l2 preferably by abayonet and slot connection, such as indicated more clearly in Fig. 4.As thus shown, a pin I3 is fixedly inserted in the Wall of the ring l2and projects inwardly a short distance into the path of the flange [5 ofthe cap in its entrance into the U space of the ring seat.

The flange I5 of the cap has a bayonet slot'or groove 19 in its outerface adapted to receive the projecting end of said pin at its entrance20 at the lower edge of the flange. Then by push- I! which effectuallypressure-seals ing inwardly on the cap and turning or twisting itclockwise slightly th slot travels so that the pin passes up into andalong the inclined portion of the groove I9 as the flange of the capenters the U groove until the upper end 2! of the groove [9 is reached,where the groove may be substantially horizontal or slightly curvedupward to provide a locking effect for the pin to prevent its beingjarred loose and tending to loosen the cap. In this position, the cap isfully and tightly sealed in the ring seat l2 and effectually closes theopening in the tank.

At least another similar pin and slot connec tion is placeddiametrically opposite across the cap and seat ring, as indicated inFig. 1, or any suitable number of such connections may be disposedsymmetrically about th seat and cap flanges.

In order that the pressure in the tank may be relieved, vented or bledtherefrom before removal of the cap, a valve 22 in the nature of ableeder valve is located in the cap Hi. This comprises a tubularprojection 23 downwardly from an aperture in the cap, the lower end ofwhich forming a valve seat is normally closed by a suitable gasket orring 24 seated in the upper face of the plunger head or valve disc 25which is carried at the lower end of the valve plunger 26 extending upthrough the tubular projection 23. Near the upper end of this plunger asuitable nut or disc 21, or a pair of them, is threaded thereon andbears on the upper end of a coiled spring 28, the lower end of which issupported on a bearing or bearings 29 preferably in the form of a ringprojecting inwardly from the wall of tubular projection 23, said ringhaving suitable apertures therein for the passage of gas or airtherethr-ough.

Normally, as shown in Fig. 2, the valve disc 25 and gasket 24 are heldup against the seat at the end of projection 23 and prevents the escapeof pressure therethrough. Any pressure in the tank adds to the closingpressure on this valve tending to hold it seated in sealing condition.

When sufficient downward pressure is exerted on the plunger 26, thevalve 25 is pushed down away from its seat, Fig. 3, and the valve isopened sufficiently to bleed and relieve the pressure from the tank andwithout discharge of the liquid therein, after which the cap may beremoved without danger.

The cap is provided with a turning flap, finger or handle wing or member3! which may be hinged as at 3! (Fig. l) to the cap and normally liesdown flatwise on the cap, as indicated in Figs. 1 and 2, but which ismanually raised up, as in Fig. 3, and grasped to handle and manipulatethe cap, as for inserting or removing it from its seat, turning ortwising it to lock or unlock it in the seat, and for other purposes, anda suitable wrench may be applied thereto if desired.

The outer edge 32 of this wing at or a portion thereof, may be turned upslightly, as indicated, to enable the fingers or a suitable tool to beworked thereunder initially to start raising the same from its proneposition on the face of the cap.

To prevent any failure in the opening of the bleeder valve 25 beforereleasing the cap from the tank, whether through ignorance,forgetfulness, carelessness, or other reason, the said handle or wing 30is preferably associated, connected or interlocked therewith, wherebyupon raising the wing from its flat position to its perpendicularposition or preparing so to do or acting preparatory to turning andreleasing the the said valve is forced and held open to relieve anypressure in the tank and thoroughly to bleed the same therefrom, so thatthe cap may be removed with ease and safety, the gas or gas and liquidare not discharged in large volume as a blast in the face of and overthe operator and there are no flying missiles like the blown-off cap.

In order to accomplish this in one way, the inner or hinged edge of thewing flap 30 may be provided with a projecting portion, lug, tongue, orlever member 33, which is arranged to bear upon the free end of bleedervalve stem or plunger 26 in such manner, as indicated, that when theflap is folded down against the face of the cap (Fig. 2) the member 33engages the end of the valve plunger 26 and the spring pressure of thelatter tends to hold the said flap 30 in that position against the faceof the cap while still holding its valve disc 25 closed. When, however,the wing 38 is raised, the member 33 depresses the plunger 26 and opensthe bleeder valve, and when so raised to the full extent, as indicatedin Fig. 3, the member 33 bears on the end of the plunger 26 and therelationship of the parts and the spring pressure are such as to holdthe wing in that upright position with the bleeder valve held open.

In this open position of the valve the gas passes up through the tubularportion 23 and around and through the spring and parts therein to escapeinto the outside air. The short length of the projection 33 as comparedto the width of the wing 3i! gives a sufficient leverage to enable thepressure of the spring and of the gas on the valve disc 25 to be readilyovercome in starting to raise the wing 39 to the open position. Thevalve spring thus tends both to hold the flap as closed and to hold itopen, the latter being a convenience in handling and manipulating thevalve and the former in keeping the wing down out of the way and freefrom chattering.

The construction and operation are thought to be clear from theforegoing. The cap cannot be removed from the pressure tank withoutoperation of the bleeder valve to relieve the pressure, if any, therein,and this is accomplished in the ordinary acts necessary to re-- move thecap, so that no new technique must be learned for the full enjoyment ofthe protection.

Without further elaboration, the foregoing will so fully explain thegist of the invention that others may, by applying current knowledge,readily adapt the same for use under varying conditions of service,Without eliminating certain features which may properly be said toconstitute the essential items of novelty involved, which items areintended to be defined and secured by the following claims.

I claim:

1. A safety cap for an opening in a pressurized gas tank comprising aU-shaped peripheral ring seat for the opening thereof, a removable capfor the opening having peripheral holding and sealing engagement withinthe U-shaped seat, a manually operated wing flap by which to manipulatesaid cap in handling and in applying the same to and removing it fromsaid seat, said flap being hinged at an edge on the top of said cap andbeing nonrotatable with respect thereto and adapted to be turned downflatly against the same or to be turned up to stand perpendicularlyupright therefrom, a spring-closed bleeder plunger valve located in thecap adjacent the hinged edge of said flap, and a projection on thehinged edge of the flap engaging said valve plunger and pressing down onthe same to open the valve when the flap is so turned up.

2. A safety cap for a wall opening in a pres surized gas tank comprisinga U-shaped ring seat for the wall opening, a removable cap for theopening having peripheral holding and sealing engagement within saidU-shaped seat, said cap being applied to and removed from said seat by arotary movement thereof, a manually operated wing flap by which tomanipulate and turn said cap in applying the same to and removing itfrom said seat, said flap being hinged at an edge to the top of said capand adapted to be turned flatly down against the same when the cap isseated and sealed or to be turned perpendicularly upright therefrom formanipulation of the cap, a spring-closed bleeder plunger valve locatedin the cap adjacent the hinged edge of said flap, and a projection onthe hinged edge of the flap engaging the top of the said valve plungerto depress the plunger and open the valve when the flap is so turned up,said plunger and. projection being arranged to hold the flap up and theplunger so depressed when the flap is in the up position and to hold theflap down and the valve closed when the flap is in the down position.

3. A safety cap for a pressurized gas tank having a ring seat for thewall opening, comprising a removable cap for the opening havingperipheral holding and sealing engagement with said seat, said cap beingapplied to and removed from said seat by a rotary movement thereof, amanually operated wing flap handle by which to handle said cap and tomanipulate and turn said cap in applying the same to and removing itfrom said seat, said flap being hinged at an edge to the top of said capand adapted to be turned down flatly against the same when not in use orto be turned perpendicularly upright therefrom when used, the cap havingan opening therein adjacent the hinged edge of said flap, a tubularprojection on the inside of the cap surrounding said opening, the lowerend of said projection forming a valve seat, a plunger valve having adisc cooperating with said seat to open and close a vent passagetherethrough, the plunger of said valve extending inwardly through saidprojection, a spring tending to close said valve disc on its said seat,a connection between said flap and plunger operating to open the valvewhen the flap is being raised, said valve disc being subject to pressurewithin the tank tending to hold the same tightly closed and sealedagainst the said seat when the cap is in position on the tank and theflap is turned down against the same.

4. A safety cap for a pressurized gas tank having a peripheral ring seatfor the opening thereof, comprising a removable cap having an openingcentrally located and a peripheral flange adapted to be retained withinthe ring seat, said flange having an annular recess on the internalsurface thereof and a plurality of slots on the external surface,corresponding projections on said ring seat adapted to engage said slotsfor locking engagement upon rotation of said cap, a resilient annulusretained in said recess adapted to contact the ring seat in sealingengagement, a

normally closed valveadapted to seal the opening in said cap, a handlemember hingedly mounted on the removable cap to facilitate the rotationand removal of said cap from the ring seat, said handle adapted to liein a, flat position against the cap when said cap is in a sealedposition, and projecting-means on the handle to depress said valve to anopen position when the handle is raised to a position normal to the capsurface whereby the valve must be opened before the cap can be rotatedand removed.

5. A safety cap for a pressurized gas tank having a U-shaped peripheralring seat for the opening thereof, comprising a removable cap having acentral cylindrica1 opening therein and a peripheral flange adapted tobe retained within said ring seat, said flange having an annular recesson the inner surface thereof and a plurality of slots on the outersurface thereof, projections on said ring seat adapted to engage saidslots in locking engagement upon rotation of the cap, a resilientannulus retained in said recess adapted to engage said ring seat insealing engagement, a manually operated handle member by which tomanipulate and turn said cap, said handle being hingedly secured to thetop of the cap and adapted to be turned to a flat position against saidcap when in the seated position, a spring-closed valve means located insaid cylindrical opening, and a projection on said handle member toengage said valve means to open the valve means when the handle memberis raised from said flat position to rotate and remove the cap.

6. A safety cap for a pressurized gas tank, comprising a U-shapedperipheral ring seat for the opening thereof, a removable cap having acentral cylindrical opening therein and a peripheral flange adapted tobe retained within said U- shaped ring seat, said flange having anannular recess on the inner surface thereof, a resilient annulusretained in said recess adapted to sealingly engage said U-shaped ringseat, the outer surface of said flanges having a plurality of slotstherein, projections on said ring seat to engage in said slots forlocking engagement upon rotation of said cap, a manually operated handlemember by which to manipulate and turn said cap, said handle beinghingedly secured to the top of the cap and adapted to be turned to aflat position against the cap when in the sealed position, a springclosed valve means located in said cylindrical opening, and a projectionat the center of said handle member to engage said valve means to openthe valve when the handle member is raised from said flat position torotate and remove the cap.

7. A safety cap for a pressurized gas tank having a U-shaped peripheralring seat for the opening thereof, comprising a removable cap having acentral cylindrical opening therein and a peripheral flange adapted tobe retained within said ring seat, said flange having an annular recesson the inner surface thereof, said cap and said ring seat havingcorresponding projections and shaped slots thereon whereby said ringseat and said cap are lockingly engaged upon rotation of said cap, aresilient annulus retained in said recess adapted to engage said ringseat in sealing engagement, a manually operated handle member by whichto manipulate and turn said cap, said handle being hingedly secured tothe top of the cap and adapted to be turned to a flat position againstsaid cap when in the seated position, a spring-closed valve meanslocated in said cylindrical opening, and a prdjection on said handlemember $50v engage said; valve means te open the valve means when the.handlemember is raised from said flat pcsitien fie rotate: and remorvelthe cap;

GHARLES FLUBACKER.

References Cited. in, the; file of. this patent;

I UNITED STATES PATENTS Number Name: Date 1,079,359 Oppenheimer V.. Nov.25, 1913 1,169,335 McManamim Jan. 25;, 19:16

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